FPS Stuttering! FPS and ping is fine, but champ stutters

Hello everyone i have an Intel i7 4790K Processor 4Ghz, G1 Nvidia GTX 980 Graphics Card 4GB, Corsair Vengeance 8gb 2133mhz overclocked memory. I should have no problems running league at max settings, however, I stutter whenever i leave my FPS uncapped. In game at max settings i will get 600 FPS at beginning going into 300 FPS during laning and 250 during team fights but i "stutter" every 5 seconds! The only thing that seems to fix this "stutter" is when i set my FPS cap at 144 but every now and then i glitch. Does anyone else experience a similar issue and if so how did you fix it?
Report as:
Offensive Spam Harassment Incorrect Board